The invention relates to a universal joint having a balancing arrangement.
European Patent Application Publication No. 385,176 A1, incorporated herein by reference, describes a balancing arrangement for a universal joint shaft in which a separate fixing ring, together with a connection tube, is fixed on a universal joint. The fixing ring encloses a partial length portion of the connection tube. On the outer face of the fixing ring, individual balancing weights can be attached by means of point welding. This arrangement, however, does not allow, especially during repair works of a joint shaft and the renewed balancing, a destruction-free disassembly. Furthermore, for such an arrangement, a high expenditure method has to be carried out, as special devices are necessary by which the balancing weights can be welded on. A faulty attachment can also only be corrected by means of a destruction. Furthermore, the position for the attachments of the balancing weights is not optimal, as the largest imbalance lies in the universal joint itself. Further, in short universal joint couplings, in which practically no connection tube is provided, up to now it was only possible to remove the masses by means of drilling-out, which leads, however, to the disadvantage, that a weakening results.
The invention, therefore, has the object to provide a universal joint having a balancing arrangement that can be made in a simple and reproducible manner and also allows in a simple way a balancing during repair works.
This object is achieved according to the invention by a universal joint having a balancing arrangement comprising two joint yokes, having, respectively, two yoke arms, in which, respectively, a support bore, centered on a common bore axis, is arranged. The support bore has a groove. The balancing arrangement further includes a journal cross assembly having four journals, of which, respectively, two are arranged on a common axis and intersect each other perpendicularly. Bearing bushings are supported on the journals and have, respectively, a bottom and an outer face. A bearing bushing is received, respectively, in each of the support bores. A retaining ring is provided in each support bore and serves to fix the bearing bushing. To accomplish this, the retaining ring engages in the groove of the support bore and is supported on the outer face of the bottom of the corresponding bearing bushing. The retaining ring has a support portion arranged radially outwardly in reference to the bore axis and abuts the bottom of the bearing bushing. The retaining ring has at least one holding portion pointing radially inwardly to the bore axis, which is axially off-set in reference to the support portion and is distanced to the bottom, thereby forming a gap. The balancing arrangement further including a balancing weight, formed as a ring, interrupted at one point, and retainable in the gap between the bottom and the at least one holding portion.
In the embodiment, it is advantageous that the balancing weight is attached where the imbalances in a universal joint are concentrated. Furthermore, it is advantageous that in case of repair works, a simple re-balancing is possible as the balancing weights are attached removably. At the same time, it is easily possible to increase the balancing accuracy by means of exchanging the weights during the balancing.
Preferably, on the support portion, three holding portions for retaining the balancing weight are provided. These are distributedly arranged on the support portion. For a secure retainment of the balancing weight, it is provided that each holding portion and the balancing weight have a first and a second contact face, respectively, which contact each other, wherein at least one of the contact faces forms part of a face of an envelope of a cone approaching away from the bore axis along the outer face of the bottom. In this case, the faces contacting each other can be formed concerning their extension path in such a way that a self-locking is achieved and, therefore, a detaching is prevented. Forces that act in the direction towards the bottom of the bearing bushing do not act on to the balancing weight, as they are directly introduced into the yoke arms of the corresponding joint yoke by means of the retaining ring.
For fixing, the balance weight has a fixing portion radially at the outside in reference to the bore axis, the fixing portion engaging in the gap of the retaining ring.
An advantageous solution is where the balancing weight has balancing segments, and the balancing segments are attached on the fixing portion radially towards the bore axis. In this case, the balancing segments can be individually detachable from the fixing portion and/or from each other.
To be able to mount the balancing weight in a simpler way, it has at least one slot extending, starting from an inner contour, radially to the outside into the fixing portion. Balancing weights with different masses can also be formed in such a way that the balancing segments in their thickness are formed differently and have different dimensions in radial direction at a constant thickness.
A universal joint shaft, in which a universal joint is provided with a balancing arrangement according to the invention, and different design possibilities for the balancing weights are represented schematically in the drawing and are described by means of these.
Various objects and advantages of this invention will become apparent to those skilled in the art from the following detailed description of the preferred embodiments, when read in light of the accompanying drawings.